Electrical connector



Aug. 22, 1961 w. A. SCHNEIDER 2,997,522

ELECTRICAL CONNECTOR Filed Aug. 4, 1960 "IIIIIIII v INVENTOR, W/LHELM A.SCHNEIDER.

A T TORNE).

United States Patent 2,997,522 ELECTRICAL CONNECTOR Wilhelm A.Schneider, Fair Haven, N.J., assignor to the United States of America asrepresented by the Secretary of the Army Filed Aug. 4, 1960, Ser. No.47,567 3 Claims. (Cl. 17484) (Granted under Title 35, US. Code (1952),see. 266) The invention described herein may be manufactured and used byor for the Government for governmental purposes, without the payment ofany royalty thereon.

This invention relates to solderless connectors of the type used forjoining the ends of electrical conductors to provide an electricalconductive joint therebetween. More particularly the invention relatesto a novel preinsulated connector which is adapted to receive thestripped ends of insulated conductors and to be crimped to provide ajoint that has good electrical conductivity and is substantiallywater-tight.

In military field operation, it is frequently necessary to make a largenumber of electrical connections between the conductors of cables,coupling telephones and the like. Such work necessarily requires arelatively simple and certain method of making connections betweenconductors under adverse environmental conditions, and still provide thedesired electrical connection.

It is an object of the present invention to provide a simple andeffective connector that is operative to produce a join-t of goodelectrical conductivity under a wide variety of environmentalconditions.

It is also an object of this invention to provide an electricalconnector which is crimped to make connection and which crimp does notrecover sufficiently when the crimping force is removed whereby thecontact resistance remains stable.

For a more detailed description of the invention, together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawing, wherein;

FIG. 1 is a longitudinal section through a connector, embodyingprinciples of this invention, applied as a coupling to a pair ofconductors;

FIG. 2 is a perspective view, on an enlarged scale, illustrating theferrule of the uncrimped connector of FIG. 1, with a cross-section areaas cut at line 22 of FIG. 1;

FIG. 3 is a side elevation of a crimped connector;

FIG. 4 is a sectional view, on an enlarged scale, taken on line 44 ofFIG. 3; and

FIG. 5 is a perspective view of a modification of the contact makingfeature of the connector.

Referring now to the drawing, FIG. 1 shows a connector comprising aplastic tube 12 molded over and around a ferrule 14 made of anelectrically conductive metal. The tube I12 is preferably made of aninsulating material, such as nylon, in order to secure the desiredphysical crimping characteristics when the tube is crimped. A seamlessmalleable copper sleeve 16, co-extensive with tube 12, forms the outercasing for connector 10. Ferrule 14, shown in detail in FIG. 2, is inthe form of a seamless tube having a generally oval cross-section and ismade of a material which combines good conductivity and high strength.One example of a suitable material is a high copper alloy.

The inner periphery of tube 12 is provided at each end with taperedentrances 18 and 20 having their widest portion at the end terminals ofconnector 10. The tapered entrances 18 and 2t) serve to guide thestripped ends 22 and 24 of a pair of similar insulated conductors 26 and28, respectively, into opposite ends of ferrule 14 so that 2,997,522Patented Aug. 22, 1961 the stripped ends are positioned in spacedrelationship therein.

A contact making member comprising a copper stud 30 is embedded in tube12 and projects through ferrule 14, near the center thereof, and extendstowards the stripped ends 22 and 24 positioned therein. Stud 30 isnormally spaced from the stripped ends 22 and 24 and is adapted to bemoved between the stripped ends and into contact therebetween bycrimping of sleeve 16. The end of stud 30 which makes contact with thestripped ends 22 and 24 is rounded to provide a dull point to preventits digging into the stripped ends when contact is made; the intentbeing to have the stud slide between the stripped ends without damagingthe conductors and simultaneously to force the stripped ends against theinner wall of ferrule 14 so that they become wedged thereagainst. It is,of course, understood that stud 30 is of suflicient width to wedge thestripped ends 22 and 24 apart, on crimping, so that they are maintainedin abutment with the inner wall of ferrule :14. The flexible quality oftube 12 permits movement of stud 30 in this fashion. The length of stud30 is such that when it is activated by crimping, it moves into ferrule14 a sufficient distance to contact both stripped ends 22 and 24.

In use, the end sections of conductors 26 and 28, to be joined, arestripped in the usual manner, but only for a length slightly greaterthan the longitudinal length of ferrule 14. Into opposite ends offerrule 14, the stripped ends 22 and 24 are inserted in spaced relationintermediate the opposing smaller arcuate portions of the ovularferrule, as shown in FIG. 2, with stud 30 projecting through the ferruleand extending toward the stripped ends. In this position, as indicatedin FIG. 1, connector 10 is crimped by a hand-tool at the sectionsdesignated 32, 34 and 36 to provide the configuration shown in FIG. 3.At sections 32, and 36, the sleeve 16 is squeezed against the insulatedportion of conductors 26 and 28, respectively. This crimping operationseals the insulating material 12 around the insulated conductors in suchmanner as to provide a water-tight enclosure around the insulatedconductors. At section 34, the crimping operation provides a goodelectrical connection between the stripped ends 22 and 24, as shown inFIG. 4, while increasing the mechanical strength of the splice. Earlyattempts to produce a connection having stable low contact resistance bycrimping were unsatisfactory due to the partial recovery fromdeformation of the crimped side of the housing or shell. This lack ofstability of the deformed section of the housing is overcome by notcrimping the more rigid ferrule 14, but by jamming the copper stud 30between the stripped ends 22 and 24. This action not only joins thestripped ends 22 and 24, but also wedges them against the inner wall offerrule 14. Thus a rigid static structure is formed which minimizesrelease of the contact pressure to a measurable degree.

The embodiment depicted in FIG. 5 is similar to the embodiment shown inFIGS. 1 through 4, except that the contact making member is in the formof a staple and comprises a metal bridging bar 38 connecting a pair ofidentical studs 40, which perform the same function as stud 3t). Studs40 project through ferrule 14, and crimping pressure on bridging bar 38wedges the stud between the stripped ends 22 and 24, which in turn arejammed against the inner wall of the ferrule.

From the foregoing description it should be apparent that the presentinvention provides a connector capable of achieving the several objectsset forth in the introductory portion of the present specification. Itwill be understood that various sizes vvill be made up for use withvarious size conductors, and in each instance a connector can be chosenin which the stripped ends can be readily inserted. In other cases, itis to be noted, the connector can be adapted for coupling a plurality ofconnectors, in which case several ferrules would be utilized.

While there has been described what is at present considered to be thepreferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention and it is therefore aimedin the appended claims to cover all such changes and modifications asfall within the true spirit and scope of the inventicn.

I claim:

'1. An electrical connector adapted to receive the stripped ends of apair of insulated electrical conductors and to be crimped to provide awater-tight electrically conductive joint between said conductors, saidconnector comprising a conductive metal ferrule formed to receive saidstripped ends in spaced relationship therein, a tube of insulatingmaterial covering said ferrule and extending beyond the end terminalsthereof, a malleable metal tube surrounding said insulating material andco-extensive therewith, an electrically conducting stud projectingthrough said metal ferrule and extending beyond the outer surfacethereof into said insulating material, whereby, upon the crimping ofsaid malleable metal tube, said stud is adapted to slidably move intoengagement between said spaced stripped ends and wedge said strippedends so that they are maintained in abutment with the inner wall of saidferrule.

2. An electrical connector adapted to receive the stripped ends of apair of insulated electrical conductors and to be crimped to provide awater-tight electrically conductive joint between said conductors, saidconnector comprising a conductive metal ferrule formed to receive saidstripped ends in spaced relationship therein, a tube of insulatingmaterial covering said ferrule and overlapping the end terminalsthereof, a malleable metal tube surrounding said insulating material andco-extensive therewith, a pair of longitudinally spaced electricallyconducting studs projecting through said metal ferrule, said studshaving external terminals extending beyond the outer surface of saidferrule and connected by a bridging bar, whereby, upon the crimping ofsaid malleable metal tube, said studs are adapted to slidably move intoengagement between said spaced stripped ends simultaneously and wedgesaid stripped ends so that they are maintained in abutment with theinner wall of said ferrule.

3. An electrical connector adapted to receive the stripped ends of apair of insulated electrical conductors and to be crimped to provide awater-tight electrically conductive joint between said conductors, saidconnector comprising a conductive metal ferrule formed to receive saidstripped ends in spaced relationship therein, a tube of insulatingmaterial covering said ferrule and overlapping the end terminalsthereof, a malleable metal tube surrounding said insulating material andco-extensive therewith, an electrically conducting stud projectingthrough said ferrule and extending toward said stripped ends, said studbeing normally spaced from the stripped ends but adapted to be movedinto contact with said stripped ends by crimping of the malleable metaltube, said ferrule being of a material more rigid than said stud sothat, when said malleable metal tube is crimped, the ferrule remains inits original form thereby permitting the stud to wedge the stripped endsagainst the inner wall of said ferrule.

No references cited.

